Metal complexes

Abstract

The present invention relates to metal complexes and to electronic devices, especially organic electroluminescent devices, comprising these metal complexes, especially as emitters, and in particular monometallic metal complex containing a hexadentate tripodal ligand in which three bidentate sub-ligands coordinate to a metal and the three bidentate sub-ligands, which may be the same or different, are joined via a bridge.

The invention claimed is: 
     
       1. A monometallic metal complex comprising a hexadentate tripodal ligand wherein three bidentate sub-ligands coordinate to a metal and the three bidentate sub-ligands, which are optionally the same or different, are joined via a bridge of formula (1): 
       
         
           
           
               
               
           
         
         wherein 
         the dotted bonds represent the bonds of the three bidentate sub-ligands to this structure; 
         X 1  is the same or different in each instance and is C, which is optionally substituted, or N; 
         X 2  is the same or different in each instance and is C, which is optionally substituted, or N; or two adjacent X 2  groups together are N, which is optionally substituted, O or S, so as to form a five-membered ring; or two adjacent X 2  groups together are C, which is optionally substituted, or N when one of the X 3  groups in the cycle is N, so as to form a five-membered ring; with the proviso that not more than two adjacent X 2  groups in each ring are N; and wherein any substituents optionally define a ring system with one another or with substituents bonded to X 1 ; 
         X 3  is C in each instance in one cycle or one X 3  group is N and the other X 3  group in the same cycle is C, wherein the X 3  groups in the three cycles are optionally selected independently, with the proviso that two adjacent X 2  groups together are C, which is optionally substituted, or N when one of the X 3  groups in the cycle is N; and 
         wherein the three bidentate ligands, apart from via the bridge of formula (1), are optionally ring-closed by a further bridge to form a cryptate, and 
         wherein at least one of the bidentate sub-ligands is a structure of formulae (L-1), (L-2), (L-3), (L-4), (L-33), (L-34), (L-41), (L-42), (L-43) or (L-44): 
       
       
         
           
           
               
               
           
         
         wherein 
         the dotted bond represents the bond of the sub-ligand to the bridge of formula (1); 
         CyC is the same or different in each instance and is a substituted or unsubstituted aryl or heteroaryl group which has 5 to 14 aromatic ring atoms and coordinates to the metal via a carbon atom in each case and which is bonded to CyD in (L-1) and (L-2) via a covalent bond and is bonded to a further CyC group in (L-4) via a covalent bond; 
         CyD is the same or different in each instance and is a substituted or unsubstituted heteroaryl group which has 5 to 14 aromatic ring atoms and coordinates to the metal via a nitrogen atom or via a carbene carbon atom and which is bonded to CyC in (L-1) and (L-2) via a covalent bond and is bonded to a further CyD group in (L-3) via a covalent bond; and 
         wherein two or more of the optional substituents together optionally define a ring system; 
       
       
         
           
           
               
               
           
         
         wherein 
         R is the same or different in each instance and is H, D, F, Cl, Br, I, N(R 1 ) 2 , CN, 
         NO 2 , OH, COOH, C(═O)N(R 1 ) 2 , Si(R 1 ) 3 , B(OR 1 ) 2 , C(═O)R 1 , P(═O)(R 1 ) 2 , S(═O)R 1 , S(═O) 2 R 1 , OSO 2 R 1 , a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl, alkoxy, or thioalkoxy group having 3 to 20 carbon atoms, wherein the alkyl, alkoxy, thioalkoxy, alkenyl, or alkynyl group is optionally substituted by one or more R 1  radicals and wherein one or more nonadjacent CH 2  groups are optionally replaced by R 1 C═CR 1 , C≡C, Si(R 1 ) 2 , C═O, NR 1 , O, S, or CONR 1 , an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and is optionally substituted in each case by one or more R 1  radicals, or an aryloxy or heteroaryloxy group which has 5 to 40 aromatic ring atoms and is optionally substituted by one or more R 1  radicals; and wherein two R radicals together optionally define a ring system; 
         R 1  is the same or different in each instance and is H, D, F, Cl, Br, I, N(R 2 ) 2 , CN, NO 2 , Si(R 2 ) 3 , B(OR 2 ) 2 , C(═O)R 2 , P(═O)(R 2 ) 2 , S(═O)R 2 , S(═O) 2 R 2 , OSO 2 R 2 , a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl, alkoxy, or thioalkoxy group having 3 to 20 carbon atoms, wherein the alkyl, alkoxy, thioalkoxy, alkenyl, or alkynyl group is optionally substituted by one or more R 2  radicals and wherein one or more nonadjacent CH 2  groups are optionally replaced by R 2 C═CR 2 , C≡C, Si(R 2 ) 2 , C═O, NR 2 , O, S, or CONR 2 , an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and is optionally substituted in each case by one or more R 2  radicals, or an aryloxy or heteroaryloxy group which has 5 to 40 aromatic ring atoms and is optionally substituted by one or more R 2  radicals; and wherein two or more R 1  radicals together optionally define a ring system; 
         R 2  is the same or different in each instance and is H, D, F, or an aliphatic, aromatic, and/or heteroaromatic organic radical having 1 to 20 carbon atoms, in which one or more hydrogen atoms may also be replaced by F; 
         * represents the position of coordination to the metal; 
         O represents the position of a bond to the group of the formula (1); and 
         X is the same or different at each instance and is CR or N, with the proviso that not more than one X symbol per cycle is N; 
       
       
         
           
           
               
               
           
         
         wherein 
         the sub-ligands (L-41) to (L-43) each coordinate to the metal via the nitrogen atom explicitly shown and the negatively charged oxygen atom, and the sub-ligand (L-44) coordinates via the two oxygen atoms; 
         X is the same or different in each instance and is CR or N, with the proviso that not more than two X per cycle are N; 
         R is the same or different in each instance and is H, D, F, Cl, Br, I, N(R 1 ) 2 , CN, NO 2 , OH, COOH, C(═O)N(R 1 ) 2 , Si(R 1 ) 3 , B(OR 1 ) 2 , C(═O)R 1 , P(═O)(R 1 ) 2 , S(═O)R 1 , S(═O) 2 R 1 , OSO 2 R 1 , a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl, alkoxy, or thioalkoxy group having 3 to 20 carbon atoms, wherein the alkyl, alkoxy, thioalkoxy, alkenyl, or alkynyl group is optionally substituted by one or more R 1  radicals and wherein one or more nonadjacent CH 2  groups are optionally replaced by R 1 C═CR 1 , C≡C, Si(R 1 ) 2 , C═O, NR 1 , O, S, or CONR 1 , an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and is optionally substituted in each case by one or more R 1  radicals, or an aryloxy or heteroaryloxy group which has 5 to 40 aromatic ring atoms and is optionally substituted by one or more R 1  radicals; and wherein two R radicals together optionally define a ring system; 
         R 1  is the same or different in each instance and is H, D, F, Cl, Br, I, N(R 2 ) 2 , CN, NO 2 , Si(R 2 ) 3 , B(OR 2 ) 2 , C(═O)R 2 , P(═O)(R 2 ) 2 , S(═O)R 2 , S(═O) 2 R 2 , OSO 2 R 2 , a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl, alkoxy, or thioalkoxy group having 3 to 20 carbon atoms, wherein the alkyl, alkoxy, thioalkoxy, alkenyl, or alkynyl group is optionally substituted by one or more R 2  radicals and wherein one or more nonadjacent CH 2  groups are optionally replaced by R 2 C═CR 2 , C≡C, Si(R 2 ) 2 , C═O, NR 2 , O, S, or CONR 2 , an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and is optionally substituted in each case by one or more R 2  radicals, or an aryloxy or heteroaryloxy group which has 5 to 40 aromatic ring atoms and is optionally substituted by one or more R 2  radicals; and wherein two or more R 1  radicals together optionally define a ring system; 
         R 2  is the same or different in each instance and is H, D, F, or an aliphatic, aromatic, and/or heteroaromatic organic radical having 1 to 20 carbon atoms, in which one or more hydrogen atoms may also be replaced by F and 
         o indicates the position of a bond to the group of the formula (1). 
       
     
     
       2. The metal complex of  claim 1 , wherein, when X 1  and/or X 2  is a substituted carbon atom and/or when two adjacent X 2  groups are a substituted nitrogen atom or a substituted carbon atom, the substituent is selected from the following substituents R:
 R is the same or different in each instance and is H, D, F, Cl, Br, I, N(R 1 ) 2 , CN, NO 2 , OH, COOH, C(═O)N(R 1 ) 2 , Si(R 1 ) 3 , B(OR 1 ) 2 , C(═O)R 1 , P(═O)(R 1 ) 2 , S(═O)R 1 , S(═O) 2 R 1 , OSO 2 R 1 , a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl, alkoxy, or thioalkoxy group having 3 to 20 carbon atoms, wherein the alkyl, alkoxy, thioalkoxy, alkenyl, or alkynyl group is optionally substituted by one or more R 1  radicals and wherein one or more nonadjacent CH 2  groups are optionally replaced by R 1 C═CR 1 , C≡C, Si(R 1 ) 2 , C═O, NR 1 , O, S, or CONR 1 , an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and is optionally substituted in each case by one or more R 1  radicals, or an aryloxy or heteroaryloxy group which has 5 to 40 aromatic ring atoms and is optionally substituted by one or more R 1  radicals; and wherein two R radicals together optionally define a ring system; 
 R 1  is the same or different in each instance and is H, D, F, Cl, Br, I, N(R 2 ) 2 , CN, NO 2 , Si(R 2 ) 3 , B(OR 2 ) 2 , C(═O)R 2 , P(═O)(R 2 ) 2 , S(═O)R 2 , S(═O) 2 R 2 , OSO 2 R 2 , a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl, alkoxy, or thioalkoxy group having 3 to 20 carbon atoms, wherein the alkyl, alkoxy, thioalkoxy, alkenyl, or alkynyl group is optionally substituted by one or more R 2  radicals and wherein one or more nonadjacent CH 2  groups are optionally replaced by R 2 C═CR 2 , C≡C, Si(R 2 ) 2 , C═O, NR 2 , O, S, or CONR 2 , an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and is optionally substituted in each case by one or more R 2  radicals, or an aryloxy or heteroaryloxy group which has 5 to 40 aromatic ring atoms and is optionally substituted by one or more R 2  radicals; and wherein two or more R 1  radicals together optionally define a ring system; 
 R 2  is the same or different in each instance and is H, D, F, or an aliphatic, aromatic, and/or heteroaromatic organic radical having 1 to 20 carbon atoms, in which one or more hydrogen atoms may also be replaced by F. 
 
     
     
       3. The metal complex of  claim 1 , wherein the group of formula (1) is selected from the structures of formulae (2) to (5): 
       
         
           
           
               
               
           
         
       
       
         
           
           
               
               
           
         
       
       
         
           
           
               
               
           
         
       
       
         
           
           
               
               
           
         
         wherein 
         R is the same or different in each instance and is H, D, F, Cl Br, I, N(R 1 ) 2 , CN, NO 2 , OH, COOH, C(═O)N(R 1 ) 2 , Si(R 1 ) 3 , B(OR 1 ) 2 , C(═O)R 1 , P(═O)(R 1 ) 2 , S(═O)R′, S(═O) 2 R 1 , OSO 2 R 1 , a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl, alkoxy, or thioalkoxy group having 3 to 20 carbon atoms, wherein the alkyl, alkoxy, thioalkoxy, alkenyl, or alkynyl group is optionally substituted by one or more R 1  radicals and wherein one or more nonadjacent CH 2  groups are optionally replaced by R 1 C═CR 1 , C≡C, Si(R 1 ) 2 , C═O, NR 1 , O, S, or CONR 1 , an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and is optionally substituted in each case by one or more R 1  radicals, or an aryloxy or heteroaryloxy group which has 5 to 40 aromatic ring atoms and is optionally substituted by one or more R 1  radicals; and wherein two R radicals together optionally define a ring system; 
         R 1  is the same or different in each instance and is H, D, F, Cl, Br, I, N(R 2 ) 2 , CN, NO 2 , Si(R 2 ) 3 , B(OR 2 ) 2 , C(═O)R 2 , P(═O)(R 2 ) 2 , S(═O)R 2 , S(═O) 2 R 2 , OSO 2 R 2 , a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl, alkoxy, or thioalkoxy group having 3 to 20 carbon atoms, wherein the alkyl, alkoxy, thioalkoxy, alkenyl, or alkynyl group is optionally substituted by one or more R 2  radicals and wherein one or more nonadjacent CH 2  groups are optionally replaced by R 2 C═CR 2 , C≡C, Si(R 2 ) 2 , C═O, NR 2 , O, S, or CONR 2 , an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and is optionally substituted in each case by one or more R 2  radicals, or an aryloxy or heteroaryloxy group which has 5 to 40 aromatic ring atoms and is optionally substituted by one or more R 2  radicals; and wherein two or more R 1  radicals together optionally define a ring system; 
         R 2  is the same or different in each instance and is H, D, F, or an aliphatic, aromatic, and/or heteroaromatic organic radical having 1 to 20 carbon atoms, in which one or more hydrogen atoms may also be replaced by F. 
       
     
     
       4. The metal complex of  claim 1 , wherein X 3  is C and the group of formula (1) is selected from formulae (2a) to (5a): 
       
         
           
           
               
               
           
         
         wherein 
         R is the same or different in each instance and is H, D, F, Cl, Br, I, N(R 1 ) 2 , CN, NO 2 , OH, COOH, C(═O)N(R 1 ) 2 , Si(R 1 ) 3 , B(OR 1 ) 2 , C(═O)R 1 , P(═O)(R 1 ) 2 , S(═O)R 1 , S(═O) 2 R 1 , OSO 2 R 1 , a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl, alkoxy, or thioalkoxy group having 3 to 20 carbon atoms, wherein the alkyl, alkoxy, thioalkoxy, alkenyl, or alkynyl group is optionally substituted by one or more R 1  radicals and wherein one or more nonadjacent CH 2  groups are optionally replaced by R 1 C═CR 1 , CC, Si(R 1 ) 2 , C═O, NR 1 , O, S, or CONR 1 , an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and is optionally substituted in each case by one or more R 1  radicals, or an aryloxy or heteroaryloxy group which has 5 to 40 aromatic ring atoms and is optionally substituted by one or more R 1  radicals; and wherein two R radicals together optionally define a ring system; 
         R 1  is the same or different in each instance and is H, D, F, Cl, Br, I, N(R 2 ) 2 , CN, NO 2 , Si(R 2 ) 3 , B(OR 2 ) 2 , C(═O)R 2 , P(═O)(R 2 ) 2 , S(═O)R 2 , S(═O) 2 R 2 , OSO 2 R 2 , a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl, alkoxy, or thioalkoxy group having 3 to 20 carbon atoms, wherein the alkyl, alkoxy, thioalkoxy, alkenyl, or alkynyl group is optionally substituted by one or more R 2  radicals and wherein one or more nonadjacent CH 2  groups are optionally replaced by R 2 C═CR 2 , C≡C, Si(R 2 ) 2 , C═O, NR 2 , O, S, or CONR 2 , an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and is optionally substituted in each case by one or more R 2  radicals, or an aryloxy or heteroaryloxy group which has 5 to 40 aromatic ring atoms and is optionally substituted by one or more R 2  radicals; and wherein two or more R 1  radicals together optionally define a ring system; 
         R 2  is the same or different in each instance and is H, D, F, or an aliphatic, aromatic, and/or heteroaromatic organic radical having 1 to 20 carbon atoms, in which one or more hydrogen atoms may also be replaced by F. 
       
     
     
       5. The metal complex of  claim 1 , wherein the bivalent arylene or heteroarylene groups in formula (1) are the same or different in each instance and are selected from formulae (7) to (31): 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         wherein 
         the dotted bond in each case represents the position of the bidentate sub-ligand; 
         * represents the position of the bond to the central trivalent aryl or heteroaryl group in formula (1); and 
         R is the same or different in each instance and is H, D, F, Cl, Br, I, N(R 1 ) 2 , CN, NO 2 , OH, COOH, C(═O)N(R 1 ) 2 , Si(R 1 ) 3 , B(OR 1 ) 2 , C(═O)R 1 , P(═O)(R 1 ) 2 , S(═O)R 1 , S(═O) 2 R 1 , OSO 2 R 1 , a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl, alkoxy, or thioalkoxy group having 3 to 20 carbon atoms, wherein the alkyl, alkoxy, thioalkoxy, alkenyl, or alkynyl group is optionally substituted by one or more R 1  radicals and wherein one or more nonadjacent CH 2  groups are optionally replaced by R 1 C═CR 1 , C≡C, Si(R 1 ) 2 , C═O, NR 1 , O, S, or CONR 1 , an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and is optionally substituted in each case by one or more R 1  radicals, or an aryloxy or heteroaryloxy group which has 5 to 40 aromatic ring atoms and is optionally substituted by one or more R 1  radicals; and wherein two R radicals together optionally define a ring system; 
         R 1  is the same or different in each instance and is H, D, F, Cl, Br, I, N(R 2 ) 2 , CN, NO 2 , Si(R 2 ) 3 , B(OR 2 ) 2 , C(═O)R 2 , P(═O)(R 2 ) 2 , S(═O)R 2 , S(═O) 2 R 2 , OSO 2 R 2 , a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl, alkoxy, or thioalkoxy group having 3 to 20 carbon atoms, wherein the alkyl, alkoxy, thioalkoxy, alkenyl, or alkynyl group is optionally substituted by one or more R 2  radicals and wherein one or more nonadjacent CH 2  groups are optionally replaced by R 2 C═CR 2 , C≡C, Si(R 2 ) 2 , C═O, NR 2 , O, S, or CONR 2 , an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and is optionally substituted in each case by one or more R 2  radicals, or an aryloxy or heteroaryloxy group which has 5 to 40 aromatic ring atoms and is optionally substituted by one or more R 2  radicals; and wherein two or more R 1  radicals together optionally define a ring system; 
         R 2  is the same or different in each instance and is H, D, F, or an aliphatic, aromatic, and/or heteroaromatic organic radical having 1 to 20 carbon atoms, in which one or more hydrogen atoms may also be replaced by F. 
       
     
     
       6. The metal complex of  claim 1 , wherein the group of formula (1) is selected from the groups of formulae (2b) to (5b): 
       
         
           
           
               
               
           
         
         wherein 
         R is the same or different in each instance and is H, D, F, Cl, Br, I, N(R 1 ) 2 , CN, NO 2 , OH, COOH, C(═O)N(R 1 ) 2 , Si(R 1 ) 3 , B(OR 1 ) 2 , C(═O)R 1 , P(═O)(R 1 ) 2 , S(═O)R 1 , S(═O) 2 R 1 , OSO 2 R 1 , a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl, alkoxy, or thioalkoxy group having 3 to 20 carbon atoms, wherein the alkyl, alkoxy, thioalkoxy, alkenyl, or alkynyl group is optionally substituted by one or more R 1  radicals and wherein one or more nonadjacent CH 2  groups are optionally replaced by R 1 C═CR 1 , C≡C, Si(R 1 ) 2 , C═O, NR 1 , O, S, or CONR 1 , an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and is optionally substituted in each case by one or more R 1  radicals, or an aryloxy or heteroaryloxy group which has 5 to 40 aromatic ring atoms and is optionally substituted by one or more R 1  radicals; and wherein two R radicals together optionally define a ring system 
         R 1  is the same or different in each instance and is H, D, F, Cl, Br, I, N(R 2 ) 2 , CN, NO 2 , Si(R 2 ) 3 , B(OR 2 ) 2 , C(═O)R 2 , P(═O)(R 2 ) 2 , S(═O)R 2 , S(═O) 2 R 2 , OSO 2 R 2 , a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl, alkoxy, or thioalkoxy group having 3 to 20 carbon atoms, wherein the alkyl, alkoxy, thioalkoxy, alkenyl, or alkynyl group is optionally substituted by one or more R 2  radicals and wherein one or more nonadjacent CH 2  groups are optionally replaced by R 2 C═CR 2 , C≡C, Si(R 2 ) 2 , C═O, NR 2 , O, S, or CONR 2 , an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and is optionally substituted in each case by one or more R 2  radicals, or an aryloxy or heteroaryloxy group which has 5 to 40 aromatic ring atoms and is optionally substituted by one or more R 2  radicals; and wherein two or more R 1  radicals together optionally define a ring system; 
         R 2  is the same or different in each instance and is H, D, F, or an aliphatic, aromatic, and/or heteroaromatic organic radical having 1 to 20 carbon atoms, in which one or more hydrogen atoms may also be replaced by F. 
       
     
     
       7. The metal complex of  claim 1 , wherein the three bidentate sub-ligands are selected identically or two of the bidentate sub-ligands are selected identically and the third bidentate sub-ligand is different from the first two bidentate sub-ligands. 
     
     
       8. The metal complex of  claim 1 , wherein the metal is selected from the group consisting of aluminium, indium, gallium, and tin, wherein the bidentate sub-ligands are the same or different in each instance and have two nitrogen atoms or two oxygen atoms or one nitrogen atom and one oxygen atom as coordinating atoms, or wherein the metal is selected from the group consisting of chromium, molybdenum, tungsten, rhenium, ruthenium, osmium, rhodium, iridium, iron, cobalt, nickel, palladium, platinum, copper, silver and gold, wherein the bidentate sub-ligands are the same or different in each instance and have one carbon atom and one nitrogen atom or two carbon atoms or two nitrogen atoms or two oxygen atoms or one oxygen atom and one nitrogen atom as coordinating atoms. 
     
     
       9. The metal complex of  claim 1 , wherein the metal is Ir(III) and two of the bidentate sub-ligands each coordinate to the iridium via one carbon atom and one nitrogen atom and the third of the bidentate sub-ligands coordinates to the iridium via one carbon atom and one nitrogen atom or via two nitrogen atoms or via one nitrogen atom and one oxygen atom or via two oxygen atoms. 
     
     
       10. The metal complex of  claim 1 , wherein CyC is selected from the structures of formulae (CyC-1) to (CyC-19), wherein the CyC group binds in each case at the position signified by # to CyD in (L-1) and (L-2) and to CyC in (L-4) and at the position signified by * to the metal, and the circle symbol ° represents a direct bond to the bridge of formula (1): 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         wherein CyD is selected from formulae (CyD-1) to (CyD-14), wherein the CyD group binds in each case at the position signified by # to CyC in (L-1) and (L-2) and to CyD in (L-3) and at the position signified by * to the metal: 
       
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         wherein 
         R is the same or different in each instance and is H, D, F, Cl, Br, I, N(R 1 ) 2 , CN, NO 2 , OH, COOH, C(═O)N(R 1 ) 2 , Si(R 1 ) 3 , B(OR 1 ) 2 , C(═O)R 1 , P(═O)(R 1 ) 2 , S(═O)R 1 , S(═O) 2 R′, OSO 2 R 1 , a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl, alkoxy, or thioalkoxy group having 3 to 20 carbon atoms, wherein the alkyl, alkoxy, thioalkoxy, alkenyl, or alkynyl group is optionally substituted by one or more R 1  radicals and wherein one or more nonadjacent CH 2  groups are optionally replaced by R 1 C═CR 1 , C≡C, Si(R 1 ) 2 , C═O, NR 1 , O, S, or CONR 1 , an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and is optionally substituted in each case by one or more R 1  radicals, or an aryloxy or heteroaryloxy group which has 5 to 40 aromatic ring atoms and is optionally substituted by one or more R 1  radicals; and wherein two R radicals together optionally define a ring system; 
         R 1  is the same or different in each instance and is H, D, F, Cl, Br, I, N(R 2 ) 2 , CN, NO 2 , Si(R 2 ) 3 , B(OR 2 ) 2 , C(═O)R 2 , P(═O)(R 2 ) 2 , S(═O)R 2 , S(═O) 2 R 2 , OSO 2 R 2 , a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl, alkoxy, or thioalkoxy group having 3 to 20 carbon atoms, wherein the alkyl, alkoxy, thioalkoxy, alkenyl, or alkynyl group is optionally substituted by one or more R 2  radicals and wherein one or more nonadjacent CH 2  groups are optionally replaced by R 2 C═CR 2 , C≡C, Si(R 2 ) 2 , C═O, NR 2 , O, S, or CONR 2 , an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and is optionally substituted in each case by one or more R 2  radicals, or an aryloxy or heteroaryloxy group which has 5 to 40 aromatic ring atoms and is optionally substituted by one or more R 2  radicals; and wherein two or more R 1  radicals together optionally define a ring system; 
         R 2  is the same or different in each instance and is H, D, F, or an aliphatic, aromatic, and/or heteroaromatic organic radical having 1 to 20 carbon atoms, in which one or more hydrogen atoms may also be replaced by F; 
         X is the same or different in each instance and is CR or N, with the proviso that not more than two X per cycle are N; and 
         W is the same or different in each instance and is NR, O, or S; 
         with the proviso that, when the bridge of formula (1) is bonded to CyC, one X is C and the bridge of formula (1) is bonded to this carbon atom and, when the bridge of formula (1) is bonded to CyD, one X is C and the bridge of formula (1) is bonded to this carbon atom. 
       
     
     
       11. The metal complex of  claim 1 , wherein at least one of the bidentate sub-ligands is selected from the structures of formulae (L-1-1), (L-1-2), and (L-2-1) to (L-2-3): 
       
         
           
           
               
               
           
         
         wherein 
         X is the same or different in each instance and is CR or N, with the proviso that not more than two X per cycle are N; 
         R is the same or different in each instance and is H, D, F, Cl, Br, I, N(R 1 ) 2 , CN, NO 2 , OH, COOH, C(═O)N(R 1 ) 2 , Si(R 1 ) 3 , B(OR 1 ) 2 , C(═O)R 1 , P(═O)(R 1 ) 2 , S(═O)R 1 , S(═O) 2 R′, OSO 2 R 1 , a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl, alkoxy, or thioalkoxy group having 3 to 20 carbon atoms, wherein the alkyl, alkoxy, thioalkoxy, alkenyl, or alkynyl group is optionally substituted by one or more R 1  radicals and wherein one or more nonadjacent CH 2  groups are optionally replaced by R 1 C═CR 1 , C≡C, Si(R 1 ) 2 , C═O, NR 1 , O, S, or CONR 1 , an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and is optionally substituted in each case by one or more R 1  radicals, or an aryloxy or heteroaryloxy group which has 5 to 40 aromatic ring atoms and is optionally substituted by one or more R 1  radicals; and wherein two R radicals together optionally define a ring system; 
         R 1  is the same or different in each instance and is H, D, F, Cl, Br, I, N(R 2 ) 2 , CN, NO 2 , Si(R 2 ) 3 , B(OR 2 ) 2 , C(═O)R 2 , P(═O)(R 2 ) 2 , S(═O)R 2 , S(═O) 2 R 2 , OSO 2 R 2 , a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl, alkoxy, or thioalkoxy group having 3 to 20 carbon atoms, wherein the alkyl, alkoxy, thioalkoxy, alkenyl, or alkynyl group is optionally substituted by one or more R 2  radicals and wherein one or more nonadjacent CH 2  groups are optionally replaced by R 2 C═CR 2 , C≡C, Si(R 2 ) 2 , C═O, NR 2 , O, S, or CONR 2 , an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and is optionally substituted in each case by one or more R 2  radicals, or an aryloxy or heteroaryloxy group which has 5 to 40 aromatic ring atoms and is optionally substituted by one or more R 2  radicals; and wherein two or more R 1  radicals together optionally define a ring system; 
         R 2  is the same or different in each instance and is H, D, F, or an aliphatic, aromatic, and/or heteroaromatic organic radical having 1 to 20 carbon atoms, in which one or more hydrogen atoms may also be replaced by F; and 
         o represents the position of the bond to the bridge of the formula (1); 
         and/or in that at least one of the bidentate sub-ligands is selected from the structures of formulae (L-5) to (L-32): 
       
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         wherein 
         X is the same or different in each instance and is CR or N, with the proviso that not more than two X per cycle are N; 
         R is the same or different in each instance and is H, D, F, Cl, Br, I, N(R 1 ) 2 , CN, NO 2 , OH, COOH, C(═O)N(R 1 ) 2 , Si(R 1 ) 3 , B(OR 1 ) 2 , C(═O)R 1 , P(═O)(R 1 ) 2 , S(═O)R 1 , S(═O) 2 R 1 , OSO 2 R 1 , a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl, alkoxy, or thioalkoxy group having 3 to 20 carbon atoms, wherein the alkyl, alkoxy, thioalkoxy, alkenyl, or alkynyl group is optionally substituted by one or more R 1  radicals and wherein one or more nonadjacent CH 2  groups are optionally replaced by R 1 C═CR 1 , C≡C, Si(R 1 ) 2 , C═O, NR 1 , O, S, or CONR 1 , an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and is optionally substituted in each case by one or more R 1  radicals, or an aryloxy or heteroaryloxy group which has 5 to 40 aromatic ring atoms and is optionally substituted by one or more R 1  radicals; and wherein two R radicals together optionally define a ring system; 
         R 1  is the same or different in each instance and is H, D, F, Cl, Br, I, N(R 2 ) 2 , CN, NO 2 , Si(R 2 ) 3 , B(OR 2 ) 2 , C(═O)R 2 , P(═O)(R 2 ) 2 , S(═O)R 2 , S(═O) 2 R 2 , OSO 2 R 2 , a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl, alkoxy, or thioalkoxy group having 3 to 20 carbon atoms, wherein the alkyl, alkoxy, thioalkoxy, alkenyl, or alkynyl group is optionally substituted by one or more R 2  radicals and wherein one or more nonadjacent CH 2  groups are optionally replaced by R 2 C═CR 2 , C≡C, Si(R 2 ) 2 , C═O, NR 2 , O, S, or CONR 2 , an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and is optionally substituted in each case by one or more R 2  radicals, or an aryloxy or heteroaryloxy group which has 5 to 40 aromatic ring atoms and is optionally substituted by one or more R 2  radicals; and wherein two or more R 1  radicals together optionally define a ring system; 
         R 2  is the same or different in each instance and is H, D, F, or an aliphatic, aromatic, and/or heteroaromatic organic radical having 1 to 20 carbon atoms, in which one or more hydrogen atoms may also be replaced by F; 
         * represents the position of coordination to the metal; and 
         o indicates the position of a direct bond to the group of the formula (1). 
       
     
     
       12. The metal complex of  claim 1 , wherein the metal complex has two substituents which are bonded to adjacent carbon atoms and together define a ring of formulae (43) to (49), and wherein R and R 1  of the metal complex refer to any substituent position on the metal complex: 
       
         
           
           
               
               
           
         
         wherein 
         R 1  is the same or different in each instance and is H, D, F, Cl, Br, I, N(R 2 ) 2 , CN, NO 2 , Si(R 2 ) 3 , B(OR 2 ) 2 , C(═O)R 2 , P(═O)(R 2 ) 2 , S(═O)R 2 , S(═O) 2 R 2 , OSO 2 R 2 , a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl, alkoxy, or thioalkoxy group having 3 to 20 carbon atoms, wherein the alkyl, alkoxy, thioalkoxy, alkenyl, or alkynyl group is optionally substituted by one or more R 2  radicals and wherein one or more nonadjacent CH 2  groups are optionally replaced by R 2 C═CR 2 , C≡C, Si(R 2 ) 2 , C═O, NR 2 , O, S, or CONR 2 , an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and is optionally substituted in each case by one or more R 2  radicals, or an aryloxy or heteroaryloxy group which has 5 to 40 aromatic ring atoms and is optionally substituted by one or more R 2  radicals; and wherein two or more R 1  radicals together optionally define a ring system; 
         R 2  is the same or different in each instance and is H, D, F, or an aliphatic, aromatic, and/or heteroaromatic organic radical having 1 to 20 carbon atoms, in which one or more hydrogen atoms may also be replaced by dotted bonds signify the linkage of the two carbon atoms in the ligand and, in addition: 
         A 1  and A 3  
 are the same or different in each instance and is C(R 3 ) 2 , O, S, NR 3 , or C(═O); 
 
         A 2  is C(R 1 ) 2 , O, S, NR 3 , or C(═O); 
         G is an alkylene group which has 1, 2, or 3 carbon atoms and is optionally substituted by one or more R 2  radicals, —CR 2 ═CR 2 —, or an ortho-bonded arylene or heteroarylene group which has 5 to 14 aromatic ring atoms and is optionally substituted by one or more R 2  radicals; 
         R 3  is the same or different in each instance and is H, F, a straight-chain alkyl or alkoxy group having 1 to 10 carbon atoms, a branched or cyclic alkyl or alkoxy group having 3 to 10 carbon atoms, wherein the alkyl or alkoxy group is optionally substituted in each case by one or more R 2  radicals, wherein one or more nonadjacent CH 2  groups are optionally replaced by R 2 C═CR 2 , C≡C, Si(R 2 ) 2 , C═O, NR 2 , O, S, or CONR 2 , an aromatic or heteroaromatic ring system which has 5 to 24 aromatic ring atoms and is optionally substituted in each case by one or more R 2  radicals, or an aryloxy or heteroaryloxy group which has 5 to 24 aromatic ring atoms and is optionally substituted by one or more R 2  radicals; and wherein two R 3  radicals bonded to the same carbon atom together optionally define an aliphatic or aromatic ring system to form a spiro system; and wherein R 3  with an adjacent R or R 1  radical optionally defines an aliphatic ring system; 
         with the proviso that no two heteroatoms in these groups are bonded directly to one another and no two C═O groups are bonded directly to one another. 
       
     
     
       13. An oligomer, polymer, or dendrimer containing one or more metal complexes of  claim 1 , wherein, rather than a hydrogen atom or a substituent, one or more bonds of the metal complex to the polymer, oligomer, or dendrimer are present. 
     
     
       14. A formulation comprising at least one metal complex of  claim 1  and at least one solvent. 
     
     
       15. A formulation comprising at least one oligomer, polymer, or dendrimer of  claim 13  and at least one solvent. 
     
     
       16. An electronic device comprising at least one metal complex of  claim 1 . 
     
     
       17. The electronic device of  claim 16 , wherein the electronic device is selected from the group consisting of organic electroluminescent devices, organic integrated circuits, organic field-effect transistors, organic thin-film transistors, organic light-emitting transistors, organic solar cells, organic optical detectors, organic photoreceptors, organic field quench devices, light-emitting electrochemical cells, oxygen sensors, oxygen sensitizers, and organic laser diodes. 
     
     
       18. An electronic device comprising at least one oligomer, polymer, or dendrimer of  claim 13 . 
     
     
       19. The electronic device of  claim 18 , wherein the electronic device is selected from the group consisting of organic electroluminescent devices, organic integrated circuits, organic field-effect transistors, organic thin-film transistors, organic light-emitting transistors, organic solar cells, organic optical detectors, organic photoreceptors, organic field quench devices, light-emitting electrochemical cells, oxygen sensors, oxygen sensitizers, and organic laser diodes. 
     
     
       20. The electronic device of  claim 16 , wherein the electronic device is an organic electroluminescent device, wherein the at least one metal complex is used as emitting compound in one or more emitting layers or as hole transport compound in a hole injection or hole transport layer or as electron transport compound in an electron transport or hole blocking layer.